MEASUREMENT OF CS-CS ELASTIC-SCATTERING AT T = 30 MU-K

We have measured the elastic collision cross section for spin polarized atomic cesium. Neutral cesium atoms are optically cooled, then loaded into a dc magnetic trap. We infer the scattering rate from the rate at which anisotropies in the initial energy distribution are observed to relax. The cross section for F = 3, m(F) = -3 on F = 3, m(F) = -3 is 1.5(4) x 10(-12) cm2, and is independent of temperature from 30 to 250 muK. This determination clarifies the technical requirements for attaining Bose-Einstein condensation in a magnetically trapped Cs vapor. We also study heating due to glancing collisions with 300 K background Cs atoms.